1. Field of the Invention
The present invention relates to a rotary compressor used for a refrigeration cycle of a refrigeration apparatus, an air conditioner, and the like.
2. Description of the Related Art
A conventional hermetically-sealed type rotary compressor, in which an inner bottom portion of a casing is used as an oil reservoir, includes a rotary compressor element which is disposed on a lower portion of the casing; and a motor element which is composed of a stator and a rotator having a permanent magnet embedded in a projection disposed on a laminated iron core and which is disposed on an upper portion of the casing. A gas refrigerant ejected from the rotary compressor element passes through the motor element and is ejected from an ejection port disposed on an upper portion of the casing to an external refrigerant circuit. The hermetically-sealed type rotary compressor is also provided with a plurality of refrigerant passing holes formed to pass through the laminated iron core of the rotator in a vertical direction so that the gas refrigerant and mist-like oil pass therethrough; an oil separation plate which is disposed above an outlet of the refrigerant passing hole, has a plurality of radial spacer portions for forming an oil separation space between the oil separation plate and the upper surface of the rotator, and is composed of a nonmagnetic material; and an insertion hole formed passing through the laminated iron core in a vertical direction to cause a fixing member, which is inserted into the spacer portions and fixes the oil separation plate to the rotator, to pass therethrough (refer to, for example, Japanese Patent Application Laid-open No. 8-28476).
Furthermore, a DC motor for driving a crank shaft of a rotary compressor is composed of a stator held in a casing of the rotary compressor; and a rotor core rotatably held in the stator and having a refrigerant path formed thereto in an axial direction. The DC motor for the rotary compressor is provided with an oil separation unit which is formed on an end plate attached to the upper end portion of the rotor core and against which a gas refrigerant flow flowing out from an upper opening of the refrigerant path collides (refer to, for example, Japanese Utility Model Application Laid-open No. 7-10486).
Furthermore, a hermetically-sealed electrically driven compressor includes a hermetically-sealed vessel including an ejection port above a predetermined position; a motor composed of a stator disposed on the hermetically-seal vessel and a rotor disposed inside of the stator; a compression mechanism unit disposed below the motor in the hermetically-sealed vessel and driven by a drive shaft inserted into the rotor with a lubricant charged to the bottom of the hermetically-sealed vessel for lubricating the compression mechanism unit; a gas flow path composed of a plurality of through holes and formed on at least the rotor of the motor so as to communicate both the upper and lower ends of the rotor in an axial direction; and an approximately disk-shaped oil separation plate held away at a predetermined interval from the upper end of the gas flow path and rotated together with the rotor. The oil separation plate has a disk plate portion and a cylindrical wall which stands at right angles with respect to the disk plate portion and which has a hollow hole formed at the center of rotation. The drive shaft is inserted into and held in the cylindrical wall by being tightly engaged therewith (refer to, for example, Japanese Patent Application Laid-open No. 2007-255214).
However, according to the conventional technology disclosed in Japanese Patent Application Laid-open No. 8-28476, since the oil separation plate, which is disposed above the outlet of the refrigerant passing hole and has a plurality of radial spacers, is used to form the oil separation space between the oil separation plate and the upper surface of the rotator, the oil separation plate has a complex shape and is made by sintering, forging, cutting, and the like. Accordingly, it has a problem that the oil separation plate becomes thick and requires a large amount of a material, and thereby a manufacturing cost is increased.
According to the conventional technology disclosed in Japanese Utility Model Application Laid-open No. 7-10486, since the oil separation unit, against which the gas refrigerant flowing out from the upper opening of the refrigerant path collides, and which is press-molded in a complex concave/convex shape, is attached to the end plate which is attached to the upper portion of the rotor core, the oil separation unit needs to be press-molded at several steps so that it is not broken in the press process. Accordingly, many press metal molds are necessary and a manufacturing cost is increased as in the above mentioned case.
According to the conventional technology disclosed in Japanese Patent Application Laid-open No. 2007-255214, the oil separation plate has the disk portion and the cylindrical wall which stands at right angles to the disk portion and has the hollow hole formed at the center of rotation, and a drive shaft is inserted into and held in the cylindrical wall so that it is tightly engaged therein. Accordingly, it is necessary to extend a drive shaft, which needs to be accurately cut, above the upper end surface of the rotor. Further the oil separation plate must be inserted to the drive shaft under pressure by a pressure-insertion device. This requires a pressure insertion step and the pressure-insertion device needs to be added. Accordingly, it has a problem that time required for processing and assembling increases, and thereby a cost is increased as in the above-mentioned case.